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//===-- llvm/CodeGen/MachineFunction.h --------------------------*- C++ -*-===//
// The LLVM Compiler Infrastructure
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
// Collect native machine code for a function. This class contains a list of
// MachineBasicBlock instances that make up the current compiled function.
// This class also contains pointers to various classes which hold
// target-specific information about the generated code.
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/Support/Annotation.h"
namespace llvm {
class Function;
class TargetMachine;
class SSARegMap;
class MachineFrameInfo;
class MachineConstantPool;
// ilist_traits
template <>
struct ilist_traits<MachineBasicBlock> {
// this is only set by the MachineFunction owning the ilist
friend class MachineFunction;
MachineFunction* Parent;
ilist_traits<MachineBasicBlock>() : Parent(0) { }
static MachineBasicBlock* getPrev(MachineBasicBlock* N) { return N->Prev; }
static MachineBasicBlock* getNext(MachineBasicBlock* N) { return N->Next; }
static const MachineBasicBlock*
getPrev(const MachineBasicBlock* N) { return N->Prev; }
static const MachineBasicBlock*
getNext(const MachineBasicBlock* N) { return N->Next; }
static void setPrev(MachineBasicBlock* N, MachineBasicBlock* prev) {
N->Prev = prev;
static void setNext(MachineBasicBlock* N, MachineBasicBlock* next) {
N->Next = next;
static MachineBasicBlock* createSentinel();
static void destroySentinel(MachineBasicBlock *MBB) { delete MBB; }
void addNodeToList(MachineBasicBlock* N);
void removeNodeFromList(MachineBasicBlock* N);
void transferNodesFromList(iplist<MachineBasicBlock,
ilist_traits<MachineBasicBlock> > &toList,
ilist_iterator<MachineBasicBlock> first,
ilist_iterator<MachineBasicBlock> last);
/// MachineFunctionInfo - This class can be derived from and used by targets to
/// hold private target-specific information for each MachineFunction. Objects
/// of type are accessed/created with MF::getInfo and destroyed when the
/// MachineFunction is destroyed.
struct MachineFunctionInfo {
virtual ~MachineFunctionInfo() {};
class MachineFunction : private Annotation {
const Function *Fn;
const TargetMachine &Target;
// List of machine basic blocks in function
ilist<MachineBasicBlock> BasicBlocks;
// Keeping track of mapping from SSA values to registers
SSARegMap *SSARegMapping;
// Used to keep track of target-specific per-machine function information for
// the target implementation.
MachineFunctionInfo *MFInfo;
// Keep track of objects allocated on the stack.
MachineFrameInfo *FrameInfo;
// Keep track of constants which are spilled to memory
MachineConstantPool *ConstantPool;
// Function-level unique numbering for MachineBasicBlocks. When a
// MachineBasicBlock is inserted into a MachineFunction is it automatically
// numbered and this vector keeps track of the mapping from ID's to MBB's.
std::vector<MachineBasicBlock*> MBBNumbering;
/// UsedPhysRegs - This is a new[]'d array of bools that is computed and set
/// by the register allocator, and must be kept up to date by passes that run
/// after register allocation (though most don't modify this). This is used
/// so that the code generator knows which callee save registers to save and
/// for other target specific uses.
bool *UsedPhysRegs;
/// LiveIns/LiveOuts - Keep track of the physical registers that are
/// livein/liveout of the function. Live in values are typically arguments in
/// registers, live out values are typically return values in registers.
/// LiveIn values are allowed to have virtual registers associated with them,
/// stored in the second element.
std::vector<std::pair<unsigned, unsigned> > LiveIns;
std::vector<unsigned> LiveOuts;
MachineFunction(const Function *Fn, const TargetMachine &TM);
/// getFunction - Return the LLVM function that this machine code represents
const Function *getFunction() const { return Fn; }
/// getTarget - Return the target machine this machine code is compiled with
const TargetMachine &getTarget() const { return Target; }
/// SSARegMap Interface... Keep track of information about each SSA virtual
/// register, such as which register class it belongs to.
SSARegMap *getSSARegMap() const { return SSARegMapping; }
void clearSSARegMap();
/// getFrameInfo - Return the frame info object for the current function.
/// This object contains information about objects allocated on the stack
/// frame of the current function in an abstract way.
MachineFrameInfo *getFrameInfo() const { return FrameInfo; }
/// getConstantPool - Return the constant pool object for the current
/// function.
MachineConstantPool *getConstantPool() const { return ConstantPool; }
/// MachineFunctionInfo - Keep track of various per-function pieces of
/// information for backends that would like to do so.
template<typename Ty>
Ty *getInfo() {
if (!MFInfo) MFInfo = new Ty(*this);
assert((void*)dynamic_cast<Ty*>(MFInfo) == (void*)MFInfo &&
"Invalid concrete type or multiple inheritence for getInfo");
return static_cast<Ty*>(MFInfo);
/// setUsedPhysRegs - The register allocator should call this to initialized
/// the UsedPhysRegs set. This should be passed a new[]'d array with entries
/// for all of the physical registers that the target supports. Each array
/// entry should be set to true iff the physical register is used within the
/// function.
void setUsedPhysRegs(bool *UPR) { UsedPhysRegs = UPR; }
/// getUsedPhysregs - This returns the UsedPhysRegs array. This returns null
/// before register allocation.
bool *getUsedPhysregs() { return UsedPhysRegs; }
const bool *getUsedPhysregs() const { return UsedPhysRegs; }
/// isPhysRegUsed - Return true if the specified register is used in this
/// function. This only works after register allocation.
bool isPhysRegUsed(unsigned Reg) { return UsedPhysRegs[Reg]; }
/// changePhyRegUsed - This method allows code that runs after register
/// allocation to keep the PhysRegsUsed array up-to-date.
void changePhyRegUsed(unsigned Reg, bool State) { UsedPhysRegs[Reg] = State; }
// LiveIn/LiveOut management methods.
/// addLiveIn/Out - Add the specified register as a live in/out. Note that it
/// is an error to add the same register to the same set more than once.
void addLiveIn(unsigned Reg, unsigned vreg = 0) {
LiveIns.push_back(std::make_pair(Reg, vreg));
void addLiveOut(unsigned Reg) { LiveOuts.push_back(Reg); }
// Iteration support for live in/out sets. These sets are kept in sorted
// order by their register number.
typedef std::vector<std::pair<unsigned,unsigned> >::const_iterator
typedef std::vector<unsigned>::const_iterator liveout_iterator;
livein_iterator livein_begin() const { return LiveIns.begin(); }
livein_iterator livein_end() const { return LiveIns.end(); }
liveout_iterator liveout_begin() const { return LiveOuts.begin(); }
liveout_iterator liveout_end() const { return LiveOuts.end(); }
/// getBlockNumbered - MachineBasicBlocks are automatically numbered when they
/// are inserted into the machine function. The block number for a machine
/// basic block can be found by using the MBB::getBlockNumber method, this
/// method provides the inverse mapping.
MachineBasicBlock *getBlockNumbered(unsigned N) {
assert(N < MBBNumbering.size() && "Illegal block number");
assert(MBBNumbering[N] && "Block was removed from the machine function!");
return MBBNumbering[N];
/// getLastBlock - Returns the MachineBasicBlock with the greatest number
MachineBasicBlock *getLastBlock() {
return MBBNumbering.back();
const MachineBasicBlock *getLastBlock() const {
return MBBNumbering.back();
/// print - Print out the MachineFunction in a format suitable for debugging
/// to the specified stream.
void print(std::ostream &OS) const;
/// viewCFG - This function is meant for use from the debugger. You can just
/// say 'call F->viewCFG()' and a ghostview window should pop up from the
/// program, displaying the CFG of the current function with the code for each
/// basic block inside. This depends on there being a 'dot' and 'gv' program
/// in your path.
void viewCFG() const;
/// viewCFGOnly - This function is meant for use from the debugger. It works
/// just like viewCFG, but it does not include the contents of basic blocks
/// into the nodes, just the label. If you are only interested in the CFG
/// this can make the graph smaller.
void viewCFGOnly() const;
/// dump - Print the current MachineFunction to cerr, useful for debugger use.
void dump() const;
/// construct - Allocate and initialize a MachineFunction for a given Function
/// and Target
static MachineFunction& construct(const Function *F, const TargetMachine &TM);
/// destruct - Destroy the MachineFunction corresponding to a given Function
static void destruct(const Function *F);
/// get - Return a handle to a MachineFunction corresponding to the given
/// Function. This should not be called before "construct()" for a given
/// Function.
static MachineFunction& get(const Function *F);
// Provide accessors for the MachineBasicBlock list...
typedef ilist<MachineBasicBlock> BasicBlockListType;
typedef BasicBlockListType::iterator iterator;
typedef BasicBlockListType::const_iterator const_iterator;
typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
typedef std::reverse_iterator<iterator> reverse_iterator;
// Provide accessors for basic blocks...
const BasicBlockListType &getBasicBlockList() const { return BasicBlocks; }
BasicBlockListType &getBasicBlockList() { return BasicBlocks; }
// BasicBlock iterator forwarding functions
iterator begin() { return BasicBlocks.begin(); }
const_iterator begin() const { return BasicBlocks.begin(); }
iterator end () { return BasicBlocks.end(); }
const_iterator end () const { return BasicBlocks.end(); }
reverse_iterator rbegin() { return BasicBlocks.rbegin(); }
const_reverse_iterator rbegin() const { return BasicBlocks.rbegin(); }
reverse_iterator rend () { return BasicBlocks.rend(); }
const_reverse_iterator rend () const { return BasicBlocks.rend(); }
unsigned size() const { return BasicBlocks.size(); }
bool empty() const { return BasicBlocks.empty(); }
const MachineBasicBlock &front() const { return BasicBlocks.front(); }
MachineBasicBlock &front() { return BasicBlocks.front(); }
const MachineBasicBlock & back() const { return BasicBlocks.back(); }
MachineBasicBlock & back() { return BasicBlocks.back(); }
// Internal functions used to automatically number MachineBasicBlocks
/// getNextMBBNumber - Returns the next unique number to be assigned
/// to a MachineBasicBlock in this MachineFunction.
unsigned addToMBBNumbering(MachineBasicBlock *MBB) {
return MBBNumbering.size()-1;
/// removeFromMBBNumbering - Remove the specific machine basic block from our
/// tracker, this is only really to be used by the MachineBasicBlock
/// implementation.
void removeFromMBBNumbering(unsigned N) {
assert(N < MBBNumbering.size() && "Illegal basic block #");
MBBNumbering[N] = 0;
// GraphTraits specializations for function basic block graphs (CFGs)
// Provide specializations of GraphTraits to be able to treat a
// machine function as a graph of machine basic blocks... these are
// the same as the machine basic block iterators, except that the root
// node is implicitly the first node of the function.
template <> struct GraphTraits<MachineFunction*> :
public GraphTraits<MachineBasicBlock*> {
static NodeType *getEntryNode(MachineFunction *F) {
return &F->front();
// nodes_iterator/begin/end - Allow iteration over all nodes in the graph
typedef MachineFunction::iterator nodes_iterator;
static nodes_iterator nodes_begin(MachineFunction *F) { return F->begin(); }
static nodes_iterator nodes_end (MachineFunction *F) { return F->end(); }
template <> struct GraphTraits<const MachineFunction*> :
public GraphTraits<const MachineBasicBlock*> {
static NodeType *getEntryNode(const MachineFunction *F) {
return &F->front();
// nodes_iterator/begin/end - Allow iteration over all nodes in the graph
typedef MachineFunction::const_iterator nodes_iterator;
static nodes_iterator nodes_begin(const MachineFunction *F) { return F->begin(); }
static nodes_iterator nodes_end (const MachineFunction *F) { return F->end(); }
// Provide specializations of GraphTraits to be able to treat a function as a
// graph of basic blocks... and to walk it in inverse order. Inverse order for
// a function is considered to be when traversing the predecessor edges of a BB
// instead of the successor edges.
template <> struct GraphTraits<Inverse<MachineFunction*> > :
public GraphTraits<Inverse<MachineBasicBlock*> > {
static NodeType *getEntryNode(Inverse<MachineFunction*> G) {
return &G.Graph->front();
template <> struct GraphTraits<Inverse<const MachineFunction*> > :
public GraphTraits<Inverse<const MachineBasicBlock*> > {
static NodeType *getEntryNode(Inverse<const MachineFunction *> G) {
return &G.Graph->front();
} // End llvm namespace